For a temperature error, there are two reasons for this: the fan has stopped functioning, or the temperature sensor has failed.
To diagnose this issue, does the fan come on ever? When you first turn on the white PCB regulator electronics, can you see the fan spin for a brief time? You may have to use a flashlight to tell if it moves. Replacing a fan can be done by your dealer (or you if you are comfortable with it), but a bad temperature sensor necessitates a repair being initiated with your dealer who will then work with you to get it to us.